Figure 6.

Relationships between fraction of dividing CD4⁺ T cells, viral load, and total CD4⁺ T cell count. The fraction of dividing CD4⁺ T cells correlates most strongly with viral load (A). This relationship was still maintained after normalizing CD4 count for each patient to 800 cells/μl (C). The fraction of dividing CD4⁺ cells also correlated inversely with CD4 count (B). This relationship was lost after normalizing viral load for each patient to 0 RNA copies/ml (D). A multiple linear regression analysis (see C and D) was conducted to determine whether viral load and CD4 count were independently predictive of CD4⁺ BrdUrd incorporation rates. The multiple linear regression equation was found to be: Log₁₀(% CD4⁺BrdUrd⁺ cells) = [Log₁₀(viral load) × 0.1652] − [(CD4 Count)*0.0003] − 3.0464; r = 0.67, P value (viral load) < 0.001, P value (CD4 count) = 0.13. The predicted CD4⁺ BrdUrd incorporation rate if CD4 counts were normalized to 800 cells/μl was calculated by the following equation: Log₁₀(% CD4 + BrdUrd⁺ cells) − [(800 cells/μl − patient's CD4 count)*0.0003]; the predicted CD4⁺ BrdUrd incorporation rate if viral loads were normalized to 0 RNA copies/ml was calculated by the following equation: Log₁₀(% CD4 + BrdUrd⁺ cells) − (patient's viral load)*0.1652. The dashed lines in A and C represent the average BrdUrd incorporation rate for CD4⁺ T cells from healthy controls. The dashed lines in B and D represent the best-fit line through the healthy control data points. Correlation coefficients and P values were determined by using Spearman Rank Order Correlation analysis.